Communication networks are known in a multitude of types. Thus a communication network that is distributed in a building and possibly across a site may be operated solely by a private operator and used only by terminals that are allocated to or authorized by the private operator. Such a communication network could, for example, be a corporate in-house communication network, which facilitates communication in the buildings and site of the company. A communication network of this type is frequently also referred to as an enterprise network.
A great many locations of interest, otherwise known as Points of Interest (PoI), may be defined in the area covered by the communication network. PoIs are known in the context of navigation systems and route planners. PoIs are locations that may be of interest for the user of a map or navigation system, such as—for example—restaurants, cash machines or filling stations. In the specific case of the area covered by the communication network, PoIs are—for example—conference rooms, workplaces, libraries, elevator accesses, etc. The PoIs may be shown on or inserted in a map as symbols. It is known, for example, for navigation systems to provide visual and audible indications of PoIs as soon as the user approaches them. Further additional information might also be stored for PoIs, such as—for example—opening times, telephone numbers, etc.
Terminals that have been set up for communication with the network nodes of the communication network have a wireless communication interface, e.g. WLAN (Wireless Area Network), DECT (Digital Enhanced Cordless Telecommunications), Bluetooth, or GSM (Global System for Mobile Communications) etc., which facilitates data interchange with the network nodes of the communication network.
The terminal or an infrastructure communicating with the terminal, e.g. the communication network, is able to determine the current position on the basis of wireless communication technology. The position may be stored in any defined system of coordinates. Thus it is now possible for any PoI to be assigned a position and for the physical coordinates to be stored in the defined coordinates system in a database that can be accessed through the communication network.
The current location may be determined by known methods of triangulation, e.g. by a plurality of network nodes in the communication network, or the degrees of latitude and longitude may be determined by means of GPS or Galileo. It is also known for a position to be determined on the basis of radio field conditions, in which the field strength of a number of network nodes of the communication network that are communicating on a wireless basis is determined.
By continuously determining the current position of the terminal, e.g. in the form of coordinates, and exchanging these coordinates with the communication network, it is possible to detect proximity to a PoI. In order to facilitate this functionality, therefore, it is necessary—in the local area covered by the communication network—to carry out measurements for each PoI, to assign the measured physical location coordinates to the defined coordinates system, and to store the data thus obtained in the database.
The disadvantage of this is the great expense of having to carry out measurements for each PoI, particularly if the communication network extends over a large area. Further problems are caused by the fact that changes in the spatial conditions may lead to changed measurement values relating to the current position of the terminal at a PoI. Such changes in the spatial conditions might, for example, be caused by furnishings being repositioned within a building, or by walls being relocated or—in particular—by walls being added.